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    <script>
        function __mix__(obj1,obj2){
            for(var k in obj2){
                obj1[k] = obj2[k];
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        var a = {
            name:'老周',
            age:18,
        }
        var b = {
            sex:'man',
        }
        __mix__(b,a);
        console.log(b);
        var o = {
            extend:function(obj){
                for (var k in obj){
                    this[k] = obj[k];
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        o.extend(a);
        console.log(o);
        
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